(FILES)Mexican tycoon Carlos Slim waves in this February 13, 2013 photo during the inauguration International Maize and Wheat Improvement Center (CIMMYT) --which was built with funds from their foundations --in Texcoco, Mexico State, Mexico. Spain's Amancio Ortega, the co-founder of the Inditex fashion group, leapt over Warren Buffett and France's Bernard Arnault to become the world's third richest person on Forbes' 2013 annual ranking of billionaires, with an estimated net worth of $57 billion. Mexico's Carlos Slim, who has taken a hit from the slump in the share price of his America Movil telecoms group since the list was calculated as of Febraury 14, remained the richest person with a fortune of $73 billion, and Microsoft co-founder Bill Gates held on to the No. 2 spot with a net worth of $67 billion.AFP PHOTO/Ronaldo Schemidt *** Local Caption *** 618055-01-08.jpg
LVMH chief executive Bernard Arnault rounds out the top 10 with a net worth of $29bn Gonzalo Fuentes / Reuters
French L'Oreal cosmetics heiress Liliane Bettencourt is ninth with $30bn. Martin Bureau / AFP Photo
Hutchison Whampoa Chairman Li Ka-shing is No 8 and the world's richest Asian businessman with a worth of $31bn. Bobby Yip / Reuters
Microsoft's Bill Gates is second with a net worth of $67 billion. Nick Adams / Reuters
Larry Ellison, the co-founder and chief executive of Oracle Corporation, is fifth and the third American with a net worth of $43bn. Fred Prouser/ Reuters
Berkshire Hathaway Chairman Warren Buffett is fourth with a net worth of $53.5bn. Rick Wilking / Reuters
David Koch, pictured, and Charles Koch are joint sixth with a net worth of $34bn. Koch Industries Inc / via Bloomberg News
Charles Koch, pictured, and David Koch are joint sixth with a net worth of $34bn. Koch Industries Inc / via Bloomberg News
Zara owner Amancio Ortega is third with a net worth of $57bn. Inditex via Bloomberg News
FILE - In a Monday, Jan. 14, 2013 file photo, Mexican telecommunications tycoon Carlos Slim speaks during news conference at the Soumaya museum in Mexico City. Forbes magazine says Monday, March 4, 2013, that Mexico's Carlos Slim remains the world's richest man for the fourth year in a row, while Warren Buffett dropped out of the top three for the first time since 2000. (AP Photo/Dario Lopez-Mills, File) *** Local Caption *** Forbes-Billionaires.JPEG-0ed8e.jpg